[Multiple posts since message is too long]
Hi, I started 3 days ago with 2 other friends and have been playing co-op as non host the entire time. The only things I did solo were completing Rise Envoy and progressing The Last Pensive to the step that needed me to speak to Orlick in the Nightfold. My 2 friends both fully finished The Last Pensive before we grouped up and I joined them, so when I joined them I think what happened was they already saw the starting cutscene of The Torment Stag and were now on that quest. I spoke to Orlick and finished The Last Pensive in a co-op session and completed the quest but didn't get a cutscene for The Torment Stag, at this point none of us knew what was supposed to be happening and we were just playing together following the sparrow.
During The Torment Stag, one of my friends bugged out on the stag boss fight and couldn't move, even after we beat the boss and the stag became uncorrupted he was still unable to move so he relogged and couldn't join back since the objective was already completed. So I talked to the stag and my other friend and I now 'finished' the quest. I then noticed that I couldn't leave the area. The vines that are supposed to teleport you back to the other teleporter would instead load the teleport bar for me and then nothing happened so I left the party and it put me back into the same area solo (also bug?) but it still wouldn't let me leave, so I relogged and joined their session again. My third friend (the one that couldn't move) who relogged was able to get back into solo and restart the quest as normal and he played it out himself since he couldn't rejoin on us.
Here's some screenshots of all faction leaders not visible and quest log showing all quests I've done and The Torment Stag as unplayable, loadout the entire time has just been the starter Oscelda gear and weapons into the Wild versions after buying the paragon bundle.